1. Field of the Invention
This invention relates to a process for the preparation of ethylene glycol monoalkyl ethers by the reaction of synthesis gas with (a) formaldehyde and an alcohol or (b) an acetal using a specific catalyst system.
2. Prior Art
There is a ever increasing need for a wide variety of glycol monoalkyl ethers of differing carbon numbers and structures which have become important present articles of commerce. Such ethers are employed in a wide variety of applications as solvents, reaction media, etc. In conventional processes an olefin oxide such as ethylene oxide is first prepared from an olefin and reacted with a suitable alcohol to give the desired glycol alkyl ether. Since the cost of materials derived from petroleum sources has been rising rapidly, research efforst are now being made to find new processes for producing these glycol ethers which do not utilize an olefin as a starting material. One of the newer methods for the preparation of glycol monoalkylethers, in which an acetal is reacted with carbon monoxide and hydrogen in the presence of a cobalt carbonyl catalyst, is described in German Pat. Nos. 875,802 and 890,945. This process suffers from several disadvantages including a low selectivity of the glycol ether and decomposition of the carbonyl catalyst during recovery of the product from the reaction mixture.
In U.S. Pat. No. 4,071,568 a process for making glycol monoalkyl ethers is disclosed in which the catalyst utilized is cobalt carbonyl combined with a trivalent organic phosphorus compound such as tri-n-butylphosphine which is reported to give better selectivity. Other process for preparing glycol monoalkyl ethers are described in U.S. Pat. No. 4,062,898 and in German Pat. No. 2,741,589.
One of the objects of this invention is to provide a novel process for preparing ethylene glycol monoalkyl ethers by means of a unique catalyst system in which the feedstock utilized comprises synthesis gas and (1) formaldehyde and an alcohol or (2) an acetal.
Another object of this invention is to provide a process for producing ethylene glycol alkyl ethers in high yield.